Device and method for data transmission in D2D communication

ABSTRACT

Embodiments of the present invention provide a device and a method for data transmission in D2D communication. The method includes: transmitting, by transmitting user equipment UE, scheduling signaling to receiving UE, where the scheduling signaling includes frequency domain resource information, a quantity of cycles that can be occupied, or transmission pattern information; and transmitting, by the transmitting UE, user data to the receiving UE according to the scheduling signaling, so that the receiving UE receives the user data according to the scheduling signaling. In the technical solution of the present invention, if there is no feedback from the receiving UE in a D2D communication process, the transmitting UE may repeatedly transmit the user data, and the receiving UE may repeatedly receive the user data, thereby improving reliability of data transmission.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/272,226, filed on Sep. 21, 2016, which is a continuation ofInternational Application No. PCT/CN2014/073897, filed on Mar. 21, 2014.All of the afore-mentioned patent applications are hereby incorporatedby reference in their entireties.

TECHNICAL FIELD

Embodiments of the present invention relate to communicationstechnologies, and in particular, to a device and a method for datatransmission in D2D communication.

BACKGROUND

If wireless communication coverage is relatively good, both an operatorand a government wish that some public safety events could be handled bywireless communication. After a safety event occurs, an emergencycommanding team and a rescue team perform communication in a geographicarea. Each team member holds a special terminal. This special terminalis referred to as a device to device (D2D) communications device or acellular D2D communications terminal device. That is, like an ordinarywireless terminal, this terminal can perform cellular communication witha base station, and can also directly communicate with another cellularD2D communications terminal device. Due to blocking of a terrain and atime-varying feature of radio signals, there is actually a cell coveragehole. In public safety requirements, it is required that a cellular D2Dcommunications terminal can be applied within network coverage andwithout network coverage. Generally, public safety personnel aremultiple persons that are grouped or clustered to take actions.

In conventional long term evolution (LTE) system, an asynchronous hybridautomatic repeat request (HARQ) mode is used for transmitting downlinkdata, and a synchronous HARQ mode is used for transmitting uplink data.

However, if an LTE HARQ mode is used in D2D communication, because thereis no feedback channel between transmitting user equipment (UE) andreceiving UE, the LTE retransmission mode cannot be used to ensurereliability of data transmission.

SUMMARY

Embodiments of the present invention provide a device and a method fordata transmission in D2D communication, which are used to implementreliable data transmission in D2D communication.

A first aspect of the present invention provides transmitting userequipment, including: a transmission module, configured to transmitscheduling signaling to receiving user equipment (UE), where thescheduling signaling includes at least one of frequency domain resourceinformation, a quantity of cycles that can be occupied, or transmissionpattern information; and a processing module, configured to transmituser data to the receiving UE according to the scheduling signaling, sothat the receiving UE receives the user data according to the schedulingsignaling.

In a first possible implementation manner of the first aspect, thescheduling signaling further includes a quantity of repetitions of adata packet; and the processing module is specifically configured to:repeatedly transmit the user data to the receiving UE according to thescheduling signaling, according to a transmission pattern indicated bythe transmission pattern information, and according to the quantity ofrepetitions of the data packet, in a frequency domain position indicatedby the frequency domain resource information, in a transmission subframeindicated by the quantity of cycles that can be occupied.

According to the first possible implementation manner of the firstaspect, in a second possible implementation manner of the first aspect,the processing module is further configured to: control an automaticrepeat request HARQ process of the transmitting UE to: obtain a firstPDU in a medium access control packet data unit MAC PDU buffer, andrecord a quantity of times of transmission as o; and if the HARQ processdetermines, according to an identifier of the HARQ process and thetransmission pattern, that a transmission subframe of the first PDUarrives, transmit the first PDU to the receiving UE by using thetransmission subframe of the first PDU, and add 1 to the quantity oftimes of transmission, until the quantity of times of transmissionreaches the quantity of repetitions of the data packet.

According to the second possible implementation manner of the firstaspect, in a third possible implementation manner of the first aspect,if a resource corresponding to the HARQ process is allocated to anothertransmitting UE for use, the processing module stops using the HARQprocess after the quantity of times of transmission reaches the quantityof repetitions of the data packet.

According to the first possible implementation manner of the firstaspect, in a fourth possible implementation manner of the first aspect,the processing module is further configured to: control a MAC PDU bufferof the transmitting UE to: transmit a second PDU to an HARQ process ofthe transmitting UE, and record a quantity of times of transmission as1, so that when the HARQ process determines that a transmission subframeof the second PDU arrives, the HARQ process transmits the second PDU tothe receiving UE by using the transmission subframe of the second PDU;and when the MAC PDU buffer determines, according to the transmissionpattern, that a minimum repetition interval expires, transmit the secondPDU to the HARQ process again, until the quantity of times oftransmission reaches the quantity of repetitions of the data packet,where the second PDU includes an identifier of the transmitting HARQprocess.

According to the first aspect, in a fifth possible implementation mannerof the first aspect, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data.

With reference to the first aspect or any one of the first to fifthpossible implementation manners of the first aspect, in a sixth possibleimplementation manner of the first aspect, the scheduling signalingfurther includes identifier information of the transmitting UE, wherethe identifier information is used to indicate a priority of using afrequency domain resource by the transmitting UE.

With reference to the first aspect or any one of the first to sixthpossible implementation manners of the first aspect, in a seventhpossible implementation manner of the first aspect, the schedulingsignaling further includes a service type of the user data to betransmitted by the transmitting UE.

With reference to the first aspect or any one of the first to seventhpossible implementation manners of the first aspect, in an eighthpossible implementation manner of the first aspect, the processingmodule is further configured to: before the transmission moduletransmits the scheduling signaling to the receiving UE, generate thescheduling signaling; or before the transmission module transmits thescheduling signaling to the receiving UE, receive the schedulingsignaling transmitted by a base station.

A second aspect of the present invention provides receiving userequipment, including: a receiving module, configured to receivescheduling signaling transmitted by transmitting user equipment (UE),where the scheduling signaling includes at least one of frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information; and a processing module, configured toreceive, according to the scheduling signaling received by the receivingmodule, user data transmitted by the transmitting UE.

In a first possible implementation manner of the second aspect, thescheduling signaling further includes a quantity of repetitions of adata packet; and the processing module is specifically configured to:repeatedly receive, according to the scheduling signaling received bythe receiving module, according to a transmission pattern indicated bythe transmission pattern information, and according to the quantity ofrepetitions of the data packet, in a frequency domain position indicatedby the frequency domain resource information, in a transmission subframeindicated by the quantity of cycles that can be occupied, the user datarepeatedly transmitted by the transmitting UE.

According to the first possible implementation manner of the secondaspect, in a second possible implementation manner of the second aspect,the processing module is further configured to: transmit, according tothe transmission pattern information, first user data in a firstsubframe in a first frame to a second automatic repeat request HARQprocess corresponding to the first subframe, and transmit, according tothe transmission pattern information, second user data in a secondsubframe in a second frame to a third HARQ process corresponding to thesecond subframe.

According to the second aspect, in a third possible implementationmanner of the second aspect, the scheduling signaling further includesan indication that a data packet is new data, where the indication thatthe data packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data; and the processingmodule is further configured to: receive, according to the schedulingsignaling received by the receiving module and according to atransmission pattern indicated by the transmission pattern information,in a frequency domain position indicated by the frequency domainresource information, in a transmission subframe indicated by thequantity of cycles that can be occupied, the new user data transmittedby the transmitting UE.

With reference to the second aspect or any one of the first to thirdpossible implementation manners of the second aspect, in a fourthpossible implementation manner of the second aspect, the schedulingsignaling further includes a service type of the user data to betransmitted by the transmitting UE; and the processing module is furtherconfigured to: create, according to the service type, a radio linkcontrol (RLC) entity corresponding to the service type; and configureparameters of the RLC entity according to a configuration tabletprestored in the receiving UE and corresponds to the service type.

A third aspect of the present invention provides transmitting userequipment, including a transmitter, a receiver, a memory, and aprocessor that is connected to the transmitter, the receiver, and thememory, where: the transmitter is configured to transmit schedulingsignaling to receiving user equipment (UE), where the schedulingsignaling includes at least one of frequency domain resourceinformation, a quantity of cycles that can be occupied, or transmissionpattern information; and the processor is configured to transmit userdata to the receiving UE according to the scheduling signaling, so thatthe receiving UE receives the user data according to the schedulingsignaling.

In a first possible implementation manner of the third aspect, thescheduling signaling further includes a quantity of repetitions of adata packet; and the processor is specifically configured to: repeatedlytransmit the user data to the receiving UE according to the schedulingsignaling, according to a transmission pattern indicated by thetransmission pattern information, and according to the quantity ofrepetitions of the data packet, in a frequency domain position indicatedby the frequency domain resource information, in a transmission subframeindicated by the quantity of cycles that can be occupied.

According to the first possible implementation manner of the thirdaspect, in a second possible implementation manner of the third aspect,the processor is further configured to: control an automatic repeatrequest HARQ process of the transmitting UE to: obtain a first PDU in amedium access control packet data unit MAC PDU buffer, and record aquantity of times of transmission as o; and if the HARQ processdetermines, according to an identifier of the HARQ process and thetransmission pattern, that a transmission subframe of the first PDUarrives, transmit the first PDU to the receiving UE by using thetransmission subframe of the first PDU, and add 1 to the quantity oftimes of transmission, until the quantity of times of transmissionreaches the quantity of repetitions of the data packet.

According to the second possible implementation manner of the thirdaspect, in a third possible implementation manner of the third aspect,if a resource corresponding to the HARQ process is allocated to anothertransmitting UE for use, the processor stops using the HARQ processafter the quantity of times of transmission reaches the quantity oftimes of repeated transmission of the data packet.

According to the first possible implementation manner of the thirdaspect, in a fourth possible implementation manner of the third aspect,the processor is further configured to: control a MAC PDU buffer of thetransmitting UE to: transmit a second PDU to an HARQ process of thetransmitting UE, and record a quantity of times of transmission as 1, sothat when the HARQ process determines that a transmission subframe ofthe second PDU arrives, the HARQ process transmits the second PDU to thereceiving UE by using the transmission subframe of the second PDU; andwhen the MAC PDU buffer determines, according to the transmissionpattern, that a minimum repetition interval expires, transmit the secondPDU to the HARQ process again, until the quantity of times oftransmission reaches the quantity of repetitions of the data packet,where the second PDU includes an identifier of the transmitting HARQprocess.

According to the third aspect, in a fifth possible implementation mannerof the third aspect, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data.

With reference to the third aspect or any one of the first to fifthpossible implementation manners of the third aspect, in a sixth possibleimplementation manner of the third aspect, the scheduling signalingfurther includes identifier information of the transmitting UE, wherethe identifier information is used to indicate a priority of using afrequency domain resource by the transmitting UE.

With reference to the third aspect or any one of the first to sixthpossible implementation manners of the third aspect, in a seventhpossible implementation manner of the third aspect, the schedulingsignaling further includes a service type of the user data to betransmitted by the transmitting UE.

With reference to the third aspect or any one of the first to seventhpossible implementation manners of the third aspect, in an eighthpossible implementation manner of the third aspect, the processor isfurther configured to: before the transmitter transmits the schedulingsignaling to the receiving UE, generate the scheduling signaling; orbefore the transmitter transmits the scheduling signaling to thereceiving UE, receive the scheduling signaling transmitted by a basestation.

A fourth aspect of the present invention provides receiving userequipment, including a transmitter, a receiver, a memory, and aprocessor that is connected to the transmitter, the receiver, and thememory, where: the receiver is configured to receive schedulingsignaling transmitted by transmitting user equipment (UE), where thescheduling signaling includes at least one of frequency domain resourceinformation, a quantity of cycles that can be occupied, or transmissionpattern information; and

-   -   the processor is configured to receive, according to the        scheduling signaling received by the receiver, user data        transmitted by the transmitting UE.

In a first possible implementation manner of the fourth aspect, thescheduling signaling further includes a quantity of repetitions of adata packet; and the processor is specifically configured to: repeatedlyreceive, according to the scheduling signaling received by the receiver,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of repetitions of thedata packet, in a frequency domain position indicated by the frequencydomain resource information, in a transmission subframe indicated by thequantity of cycles that can be occupied, the user data repeatedlytransmitted by the transmitting UE.

According to the first possible implementation manner of the fourthaspect, in a second possible implementation manner of the fourth aspect,the processor is further configured to: transmit, according to thetransmission pattern information, first user data in a first subframe ina first frame to a second automatic repeat request HARQ processcorresponding to the first subframe, and transmit, according to thetransmission pattern information, second user data in a second subframein a second frame to a third HARQ process corresponding to the secondsubframe.

According to the fourth aspect, in a third possible implementationmanner of the fourth aspect, the scheduling signaling further includesan indication that a data packet is new data, where the indication thatthe data packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data; and the processor isfurther configured to: receive, according to the scheduling signalingreceived by the receiver and according to a transmission patternindicated by the transmission pattern information, in a frequency domainposition indicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied, the new user data transmitted by the transmitting UE.

With reference to the fourth aspect or any one of the first to thirdpossible implementation manners of the fourth aspect, in a fourthpossible implementation manner of the fourth aspect, the schedulingsignaling further includes a service type of the user data to betransmitted by the transmitting UE; and the processor is furtherconfigured to: create, according to the service type, a radio linkcontrol (RLC) entity corresponding to the service type; and configureparameters of the RLC entity according to a configuration tableprestored in the receiving UE and corresponds to the service type.

A fifth aspect of the present invention provides a method for datatransmission in D2D communication, where the method includes:transmitting, by transmitting user equipment (UE), scheduling signalingto receiving UE, where the scheduling signaling includes at least one offrequency domain resource information, a quantity of cycles that can beoccupied, or transmission pattern information; and transmitting, by thetransmitting UE, user data to the receiving UE according to thescheduling signaling, so that the receiving UE receives the user dataaccording to the scheduling signaling.

In a first possible implementation manner of the fifth aspect, thescheduling signaling further includes a quantity of repetitions of adata packet; and the transmitting, by the transmitting UE, user data tothe receiving UE according to the scheduling signaling, includes:repeatedly transmitting, by the transmitting UE, the user data to thereceiving UE according to the scheduling signaling, according to atransmission pattern indicated by the transmission pattern information,and according to the quantity of repetitions of the data packet, in afrequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied.

According to the first possible implementation manner of the fifthaspect, in a second possible implementation manner of the fifth aspect,the repeatedly transmitting, by the transmitting UE, the user data tothe receiving UE according to the scheduling signaling, according to atransmission pattern indicated by the transmission pattern information,and according to the quantity of repetitions of the data packet, in afrequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied, includes: obtaining, by an automatic repeatrequest HARQ process of the transmitting UE, a first PDU in a mediumaccess control packet data unit MAC PDU buffer, and recording a quantityof times of transmission as o; and if the HARQ process of thetransmitting UE determines, according to an identifier of the HARQprocess and the transmission pattern, that a transmission subframe ofthe first PDU arrives, transmitting the first PDU to the receiving UE byusing the transmission subframe of the first PDU, and adding 1 to thequantity of times of transmission, until the quantity of times oftransmission reaches the quantity of repetitions of the data packet.

According to the second possible implementation manner of the fifthaspect, in a third possible implementation manner of the fifth aspect,if a resource corresponding to the HARQ process is allocated to anothertransmitting UE for use, the transmitting UE stops using the HARQprocess after the quantity of times of transmission reaches the quantityof repetitions of the data packet.

According to the first possible implementation manner of the fifthaspect, in a fourth possible implementation manner of the fifth aspect,the repeatedly transmitting, by the transmitting UE, the user data tothe receiving UE according to the scheduling signaling, according to atransmission pattern indicated by the transmission pattern information,and according to the quantity of repetitions of the data packet, in afrequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied, includes: transmitting, by a MAC PDU bufferof the transmitting UE, a second PDU to an HARQ process of thetransmitting UE, and recording a quantity of times of transmission as 1,so that when the HARQ process determines that a transmission subframe ofthe second PDU arrives, the HARQ process transmits the second PDU to thereceiving UE by using the transmission subframe of the second PDU; andwhen the MAC PDU buffer of the transmitting UE determines, according tothe transmission pattern, that a minimum repetition interval expires,transmitting the second PDU to the HARQ process again, until thequantity of times of transmission reaches the quantity of repetitions ofthe data packet, where the second PDU includes an identifier of thetransmitting HARQ process.

According to the fifth aspect, in a fifth possible implementation mannerof the fifth aspect, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data.

With reference to the fifth aspect or any one of the first to fifthpossible implementation manners of the fifth aspect, in a sixth possibleimplementation manner of the fifth aspect, the scheduling signalingfurther includes identifier information of the transmitting UE, wherethe identifier information is used to indicate a priority of using afrequency domain resource by the transmitting UE.

With reference to the fifth aspect or any one of the first to sixthpossible implementation manners of the fifth aspect, in a seventhpossible implementation manner of the fifth aspect, the schedulingsignaling further includes a service type of the user data to betransmitted by the transmitting UE.

With reference to the fifth aspect or any one of the first to seventhpossible implementation manners of the fifth aspect, in an eighthpossible implementation manner of the fifth aspect, before thetransmitting, by the transmitting UE, scheduling signaling to receivingUE, the method further includes: generating, by the transmitting UE, thescheduling signaling; or receiving, by the transmitting UE, thescheduling signaling transmitted by a base station.

A sixth aspect of the present invention provides a method for datatransmission in D2D communication, where the method includes: receiving,by receiving user equipment (UE), scheduling signaling transmitted bytransmitting UE, where the scheduling signaling includes at least one offrequency domain resource information, a quantity of cycles that can beoccupied, or transmission pattern information; and receiving, by thereceiving UE according to the scheduling signaling, user datatransmitted by the transmitting UE.

In a first possible implementation manner of the sixth aspect, thescheduling signaling further includes a quantity of repetitions of adata packet; and the receiving, by the receiving UE according to thescheduling signaling, user data transmitted by the transmitting UE,includes: repeatedly receiving, by the receiving UE according to thescheduling signaling, according to a transmission pattern indicated bythe transmission pattern information, and according to the quantity ofrepetitions of the data packet, in a frequency domain position indicatedby the frequency domain resource information, in a transmission subframeindicated by the quantity of cycles that can be occupied, the user datarepeatedly transmitted by the transmitting UE.

According to the first possible implementation manner of the sixthaspect, in a second possible implementation manner of the sixth aspect,the repeatedly receiving, by the receiving UE according to thescheduling signaling, according to a transmission pattern indicated bythe transmission pattern information, and according to the quantity ofrepetitions of the data packet, in a frequency domain position indicatedby the frequency domain resource information, in a transmission subframeindicated by the quantity of cycles that can be occupied, the user datarepeatedly transmitted by the transmitting UE, includes: transmitting,by the receiving UE according to the transmission pattern information,first user data in a first subframe in a first frame to a secondautomatic repeat request HARQ process corresponding to the firstsubframe, and transmitting, by the receiving UE according to thetransmission pattern information, second user data in a second subframein a second frame to a third HARQ process corresponding to the secondsubframe.

According to the sixth aspect, in a third possible implementation mannerof the sixth aspect, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data; and the receiving, bythe receiving UE according to the scheduling signaling, user datatransmitted by the transmitting UE, includes: receiving, by thereceiving UE according to the scheduling signaling and according to atransmission pattern indicated by the transmission pattern information,in a frequency domain position indicated by the frequency domainresource information, in a transmission subframe indicated by thequantity of cycles that can be occupied, the new user data transmittedby the transmitting UE.

With reference to the sixth aspect or any one of the first to thirdpossible implementation manners of the sixth aspect, in a fourthpossible implementation manner of the sixth aspect, the schedulingsignaling further includes a service type of the user data to betransmitted by the transmitting UE; and the method further includes:creating, by the receiving UE according to the service type, a radiolink control (RLC) entity corresponding to the service type; andconfiguring, by the receiving UE, parameters of the RLC entity accordingto a configuration table prestored in the receiving UE and correspondsto the service type.

In the device and method for data transmission in D2D communication thatare provided by the embodiments, a transmission module transmitsscheduling signaling to the receiving UE, where the scheduling signalingincludes at least one of frequency domain resource information, aquantity of cycles that can be occupied, or transmission patterninformation; and a processing module transmits user data to thereceiving UE according to the scheduling signaling, so that thereceiving UE receives the user data according to the schedulingsignaling. Therefore, if there is no feedback from the receiving UE in aD2D communication process, the transmitting UE can repeatedly transmitthe user data, and the receiving UE can repeatedly receive the user dataand perform combination processing on the repeatedly received data,thereby improving reliability of data transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the following briefly describes the accompanyingdrawings required for describing the embodiments or the prior art.Apparently, the accompanying drawings in the following description showsome embodiments of the present invention, and a person of ordinaryskill in the art may still derive other drawings from these accompanyingdrawings without creative efforts.

FIG. 1 is a schematic structural diagram of Embodiment 1 of transmittinguser equipment according to the present invention;

FIG. 2 is a schematic diagram of a transmission pattern in schedulingsignaling;

FIG. 3 is a schematic diagram of UE;

FIG. 4 is a schematic diagram of a correspondence between a transmissionsubframe number and an HARQ process identifier;

FIG. 5 is a schematic structural diagram of Embodiment 2 of transmittinguser equipment according to the present invention;

FIG. 6 is a schematic structural diagram of Embodiment 1 of receivinguser equipment according to the present invention;

FIG. 7 is a schematic structural diagram of Embodiment 2 of receivinguser equipment according to the present invention;

FIG. 8 is a flowchart of Embodiment 1 of a method for data transmissionin D2D communication according to the present invention;

FIG. 9 is a flowchart of Embodiment 2 of a method for data transmissionin D2D communication according to the present invention; and

FIG. 10 is a flowchart of Embodiment 3 of a method for data transmissionin D2D communication according to the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

To make the objectives, technical solutions, and advantages of theembodiments of the present invention clearer, the following clearlydescribes the technical solutions in the embodiments of the presentinvention with reference to the accompanying drawings in the embodimentsof the present invention. Apparently, the described embodiments are somebut not all of the embodiments of the present invention. All otherembodiments obtained by a person of ordinary skill in the art based onthe embodiments of the present invention without creative efforts shallfall within the protection scope of the present invention.

FIG. 1 is a schematic structural diagram of Embodiment 1 of transmittinguser equipment according to the present invention. As shown in FIG. 1,the transmitting user equipment in this embodiment includes atransmission module 11 and a processing module 12. The transmissionmodule 11 is configured to transmit scheduling signaling to receivingUE, where the scheduling signaling includes at least one of frequencydomain resource information, a quantity of cycles that can be occupied,or transmission pattern information. The processing module 12 isconfigured to transmit user data to the receiving UE according to thescheduling signaling, so that the receiving UE receives the user dataaccording to the scheduling signaling.

Specifically, the frequency domain resource information in thescheduling information in this embodiment may include a frequency domainresource index or a maximum frequency domain resource range. If only oneuser transmits data at a same transmission time, the frequency domainresource information may be a maximum frequency domain resource range.If multiple users transmit data at a same transmission time, thefrequency domain resource information is a frequency domain resourceindex, and the quantity of cycles that can be occupied is used toindicate a quantity of cycles that can be occupied by the user datatransmitted by the transmitting UE.

FIG. 2 is a schematic diagram of a transmission pattern in thescheduling signaling. The transmission pattern information may includetime that can be occupied by the transmitting UE in a cycle and arepetition mode of a data packet. As shown in FIG. 2, UE A may occupythe first and the third milliseconds for transmission in every eightmilliseconds. The repetition mode of the data packet may include animmediate repetition, that is, a same data packet may be transmitted inthe first and third milliseconds, or a discontinuous repetition and aminimum repetition interval, that is, after being transmitted, a datapacket can be transmitted repeatedly only after waiting for a period oftime. For example, in FIG. 2, a piece of data is transmitted in thefirst millisecond, and the data packet can be transmitted again onlyafter waiting for 8 ms or a longer time.

Specifically, the scheduling signaling in this embodiment may include atleast one of the frequency domain resource information, the quantity ofcycles that can be occupied, and the transmission pattern information.If only one or two of the information are included, the other two or oneof the information is fixed.

For example, in a scenario in which the scheduling signaling in thisembodiment includes only the frequency domain resource information, thetransmission pattern information and the quantity of cycles that can beoccupied are fixed. In a scenario in which the scheduling signaling inthis embodiment includes only the quantity of cycles that can beoccupied, the frequency domain resource information and the transmissionpattern information are fixed. It may be specified that a fixedcorrespondence exists between a frequency domain position occupied bythe scheduling signaling and a frequency domain position occupied by theuser data. For example, if the scheduling signaling is transmitted in athird symbol of every two physical resource blocks (PRB), datainformation is transmitted in any symbol except the third symbol and apilot symbol in the two PRBs. In a scenario in which the schedulingsignaling in this embodiment includes only the transmission patterninformation, the frequency domain resource information and the quantityof cycles that can be occupied are fixed.

The processing module 12 of the transmitting UE transmits theto-be-transmitted user data according to the frequency domain resourceinformation, the quantity of cycles that can be occupied, and thetransmission pattern information in the scheduling signaling, in afrequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied; and the receiving UE receives, according tothe transmission pattern indicated by the transmission patterninformation, in the frequency domain position indicated by the frequencydomain resource information, in the transmission subframe indicated bythe quantity of cycles that can be occupied, the user data transmittedby the transmitting UE.

According to the transmitting user equipment provided by thisembodiment, repeated transmission of user data is determined by aprocessing module 12 of the transmitting UE according to schedulingsignaling, and is not determined according to whether there is anyfeedback from receiving UE. Therefore, if there is no feedback from thereceiving UE in a D2D communication process, the transmitting UE mayrepeatedly transmit the user data, and the receiving UE may repeatedlyreceive the user data and perform combination processing on the receivedrepeated data, thereby improving reliability of data transmission.

In the transmitting user equipment provided by this embodiment, atransmission module 11 transmits scheduling signaling to receiving UE,where the scheduling signaling includes at least one of frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information; and a processing module 12 transmitsuser data to the receiving UE according to the scheduling signaling, sothat the receiving UE receives the user data according to the schedulingsignaling. Therefore, if there is no feedback from the receiving UE in aD2D communication process, the transmitting UE may repeatedly transmitthe user data, and the receiving UE may repeatedly receive the user dataand perform combination processing on the received repeated data,thereby improving reliability of data transmission.

In an embodiment, the scheduling signaling further includes a quantityof times of repeated transmission of a data packet; and the processingmodule 12 is specifically configured to: repeatedly transmit the userdata to the receiving UE according to the scheduling signaling,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of times of repeatedtransmission of the data packet, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied.

In an embodiment, the processing module 12 is further configured to:control an HARQ process of the transmitting UE to obtain a first PDU ina medium access control (MAC) packet data unit (PDU) buffer, and recorda quantity of times of transmission as o; and if the HARQ processdetermines, according to an identifier of the HARQ process and thetransmission pattern, that a transmission subframe of the first PDUarrives, transmit the first PDU to the receiving UE by using thetransmission subframe of the first PDU, and add 1 to the quantity oftimes of transmission, until the quantity of times of transmissionreaches the quantity of times of repeated transmission of the datapacket.

FIG. 3 is a schematic diagram of UE. As shown in FIG. 3, a radio linkcontrol (RLC) module and a MAC module exist in the UE. The MAC moduleincludes a PDU buffer and an HARQ process. The HARQ process isconfigured to perform data transmission (including initial transmissionand repeated transmission), perform data reception and combinationcheck, and deliver data to the PDU buffer. A quantity of HARQ processesis defined according to a processing capability of the UE. In a cellularsystem, generally, it is considered that there are eight HARQ processes.In a multiple-input multiple-output system, there may be 16 HARQprocesses. For a D2D group user, a case of coexistence of D2Dcommunication and cellular communication may occur, or either of D2Dcommunication and cellular communication may occur. For convenient andsimple implementation of the UE, HARQ processes may be used by thecellular communication and the D2D communication jointly. That is, whenthere is only cellular communication, all the HARQ processes areoccupied by cellular communication. When there is only D2Dcommunication, all the HARQ processes are occupied by the D2Dcommunication. When there are both D2D communication and cellularcommunication, they separately occupy some HARQ processes.

In this embodiment, it may be assumed that there is only D2Dcommunication, and that all the HARQ processes may be occupied by theD2D communication.

When the UE is used as transmitting UE, for example, it is determined,according to the information in the scheduling signaling, that data maybe transmitted in two time subframes, and therefore, the UE decides thattwo services, namely, one service represented by RLC 3 and anotherservice represented by RLC 5, are both used to transmit data. Therefore,data packets of two services exist in the MAC PDU buffer, wherequantities of times of repeated transmission of the data packets of theservices may be the same or may be different. The following uses anexample in which quantities of times of repeated transmission are thesame, where RLC 3 represents a voice service, RLC 5 represents a picturetransmission service, and maximum quantities of times of repeatedtransmission of the two services are both 4. Multiple data packets areseparately generated in the two services, and transmitted to the MAC PDUbuffer. An HARQ process fetches a new PDU from the MAC PDU bufferaccording to a transmission status of the HARQ process after a previousdata packet is repeatedly transmitted for four times, and records aquantity of times of transmission as o; after a transmission subframe ofthe UE arrives, the HARQ process transmits the new PDU, and changes thequantity of times of transmission Tx_NB to Tx_NB+1 after transmission;when the quantity of times of transmission reaches an allowed maximumquantity of times of repeated transmission, namely, Tx_NB=4, the HARQprocess fetches new data from the MAC PDU buffer; after a MAC PDU isfetched by the HARQ process, the fetched MAC PDU is deleted from the MACPDU buffer.

FIG. 4 is a schematic diagram of a correspondence between a transmissionsubframe number and an HARQ process identifier. As shown in FIG. 4, aconversion relationship between a transmission subframe number and anHARQ process identifier is: (frame number*10+subframe number) mod 8=1&2.By using this formula, the HARQ process may calculate whether a nextsubframe is a subframe for transmitting data by the HARQ process. Thecalculation process may also be performed a longer time in advance. Datatransmission is completed by a physical layer. The identifier of theHARQ process used in transmission is obtained through calculationaccording to the transmission pattern in the scheduling signaling. Thatis, the transmitting UE uses HARQ processes 1 and 2 to processtransmission of MAC PDUs, and the receiving UE demodulates the receiveddata and then transmits the data to a process whose HARQ processidentifier is 1 or 2 for processing.

In an embodiment, if a resource corresponding to a first HARQ process isallocated to another transmitting UE for use, the processing module 12stops using the first HARQ process after the quantity of times oftransmission reaches the quantity of times of repeated transmission ofthe data packet.

For example, processing after the transmission pattern of thetransmitting UE is changed is described in this embodiment. When UE B ina D2D group has service data of a higher priority for transmission, atransmission resource of UE A is preempted by UE B, and transmissionresources of UE A are reduced. For example, in each frame, two subframesthat may transmit data of UE A are reduced to only one subframe that maytransmit data of UE A. Therefore, a case in which data in an HARQprocess buffer cannot be transmitted again but a quantity of times ofrepeated transmission is not completed yet may occur, and this isbecause the HARQ process is associated with a transmission subframenumber. To ensure reliable data transmission, UE A may not use theprocess any longer after continuing to repeatedly transmit the data inthe HARQ process buffer for a remaining quantity of times. Afterobtaining information indicating that the resource may be used, UE Bstarts to use the resource after waiting for a period equal to aquantity of repetitions multiplied by a repetition interval.

In the transmitting user equipment provided by this embodiment, atransmission module 11 of the transmitting UE transmits schedulingsignaling to receiving UE, where the scheduling signaling includesfrequency domain resource information, a quantity of cycles that can beoccupied, transmission pattern information, and a quantity of times ofrepeated transmission of a data packet; and a processing module 12 ofthe transmitting UE repeatedly transmits user data to the receiving UEaccording to the scheduling signaling, according to a transmissionpattern indicated by the transmission pattern information, and accordingto the quantity of times of repeated transmission of the data packet, ina frequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied. Therefore, if there is no feedback from thereceiving UE in a D2D communication process, the transmitting UE mayrepeatedly transmit the user data, and the receiving UE may repeatedlyreceive the user data and perform combination processing on the receivedrepeated data, thereby improving reliability of data transmission.

In an embodiment, the processing module 12 is further configured to:control a MAC PDU buffer of the transmitting UE to: transmit a secondPDU to an HARQ process of the transmitting UE, and record a quantity oftimes of transmission as 1, so that when the HARQ process determinesthat a transmission subframe of the first PDU arrives, the HARQ processtransmits the second PDU to the receiving UE by using the transmissionsubframe of the second PDU; and when the MAC PDU buffer determines,according to the transmission pattern, that a minimum repetitioninterval expires, transmit the second PDU to the HARQ process again,until the quantity of times of transmission reaches the quantity oftimes of repeated transmission of the data packet, where the second PDUincludes an identifier of the transmitting HARQ process.

Specifically, after the HARQ process fetches data, the MAC PDU buffer ofthe transmitting end may continue to reserve the PDU, and change acounter value from Current_TX_NB to Current_TX_NB+1. The HARQ processfetches data from a MAC PDU when performing transmission every time, andthe MAC PDU buffer provides appropriate data to the HARQ processaccording to a transmission status and a repetition status of a PDU. Forexample, if the transmitting UE obtains transmission capabilities of twoconsecutive subframes in a frame, a first subframe transmits a MAC PDU1, and a second subframe must transmit a MAC PDU 2 and cannot continueto transmit the MAC PDU 1, because the scheduling signaling requiresthat a repeated transmission interval of each packet should not be o.Therefore, when the repeated transmission interval is satisfied, the MACPDU buffer provides a repeated data packet to the HARQ process, and acase in which data packets transmitted at the first time andsubsequently repeatedly transmitted use different subframe numbers mayoccur. In this case, the transmitting UE needs to notify, in the datapacket, a process number used by the transmitting UE to the receivingend, so that the receiving UE can combine the received repeated data.After receiving a new data packet, the receiving UE demodulates the datapacket into soft bits and then transmits the soft bits to an HARQprocess buffer corresponding to the data packet, and after a repeatedpacket of the data packet arrives, also transmits soft bits to acorresponding HARQ process buffer according to a process number carriedin the repeated packet and performs combination.

In the transmitting user equipment provided by this embodiment, atransmission module 11 of the transmitting UE transmits schedulingsignaling to receiving UE, where the scheduling signaling includesfrequency domain resource information, a quantity of cycles that can beoccupied, transmission pattern information, and a quantity of times ofrepeated transmission of a data packet; and a processing module 12 ofthe transmitting UE repeatedly transmits user data to the receiving UEaccording to the scheduling signaling, according to a transmissionpattern indicated by the transmission pattern information, and accordingto the quantity of times of repeated transmission of the data packet, ina frequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied. Therefore, if there is no feedback from thereceiving UE in a D2D communication process, the transmitting UE mayrepeatedly transmit the user data, and the receiving UE may repeatedlyreceive the user data and perform combination processing on the receivedrepeated data, thereby improving reliability of data transmission.

In an embodiment, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data.

Specifically, if the user data to be transmitted by the transmitting UEis new data, the scheduling signaling further includes the indicationthat the data packet is new data; if the user data to be transmitted bythe transmitting UE is data that is transmitted repeatedly, thescheduling signaling does not include the indication that the datapacket is new data.

In an embodiment, the scheduling signaling further includes identifierinformation of the transmitting UE, where the identifier information isused to indicate a priority of using a frequency domain resource by thetransmitting UE.

Specifically, the identifier information of the UE may be a globalidentifier in a large area, or may be an intra-group identifierallocated by a group owner. The identifier information of the UE has ameaning indicating a priority. If another UE also uses a same resource,after the UE detects a collision, UE having smaller UE identifierinformation may preferentially use the resource.

In an embodiment, the scheduling signaling further includes a servicetype of the user data to be transmitted by the transmitting UE.

In an embodiment, the processing module 12 is further configured to:before the transmission module 11 transmits the scheduling signaling tothe receiving UE, generate the scheduling signaling; or before thetransmission module 11 transmits the scheduling signaling to thereceiving UE, receive the scheduling signaling transmitted by a basestation.

Specifically, the scheduling signaling transmitted by the transmissionmodule 11 of the transmitting UE to the receiving UE may be generated bythe transmitting UE, or may be received by the transmitting UE from thebase station.

In the transmitting user equipment provided by this embodiment, atransmission module 11 of the transmitting UE transmits schedulingsignaling to receiving UE, where the scheduling signaling includesfrequency domain resource information, a quantity of cycles that can beoccupied, or transmission pattern information; and a processing module12 of the transmitting UE transmits user data to the receiving UEaccording to the scheduling signaling, so that the receiving UE receivesthe user data according to the scheduling signaling. Therefore, if thereis no feedback from the receiving UE in a D2D communication process, thetransmitting UE may repeatedly transmit the user data, and the receivingUE may repeatedly receive the user data and perform combinationprocessing on the received repeated data, thereby improving reliabilityof data transmission.

FIG. 5 is a schematic structural diagram of Embodiment 2 of transmittinguser equipment according to the present invention. As shown in FIG. 5,the transmitting user equipment in this embodiment includes atransmitter 21, a receiver 22, a memory 23, and a processor 24 that isconnected to the transmitter 21, the receiver 22, and the memory 23.Certainly, the user equipment may further include a universal componentsuch as an antenna, a baseband processing unit, an intermediate radiofrequency processing unit, or an input and output apparatus, which isnot limited any longer in the embodiment of the present invention.

The transmitter 21 is configured to transmit scheduling signaling toreceiving UE, where the scheduling signaling includes at least one offrequency domain resource information, a quantity of cycles that can beoccupied, or transmission pattern information; and the processor 24 isconfigured to transmit user data to the receiving UE according to thescheduling signaling, so that the receiving UE receives the user dataaccording to the scheduling signaling.

In an embodiment, the scheduling signaling further includes a quantityof times of repeated transmission of a data packet; and the processor 24is specifically configured to: repeatedly transmit the user data to thereceiving UE according to the scheduling signaling, according to atransmission pattern indicated by the transmission pattern information,and according to the quantity of times of repeated transmission of thedata packet, in a frequency domain position indicated by the frequencydomain resource information, in a transmission subframe indicated by thequantity of cycles that can be occupied.

In an embodiment, the processor 24 is further configured to: control anautomatic repeat request HARQ process of the transmitting UE to: obtaina first PDU in a medium access control packet data unit MAC PDU buffer,and record a quantity of times of transmission as o; and if the HARQprocess determines, according to an identifier of the HARQ process andthe transmission pattern, that a transmission subframe of the first PDUarrives, transmit the first PDU to the receiving UE by using thetransmission subframe of the first PDU, and add 1 to the quantity oftimes of transmission, until the quantity of times of transmissionreaches the quantity of times of repeated transmission of the datapacket.

In an embodiment, if a resource corresponding to a first HARQ process isallocated to another transmitting UE for use, the processor 24 stopsusing the first HARQ process after the quantity of times of transmissionreaches the quantity of times of repeated transmission of the datapacket.

In an embodiment, the processor 24 is further configured to: control aMAC PDU buffer of the transmitting UE to: transmit a second PDU to anHARQ process of the transmitting UE, and record a quantity of times oftransmission as 1, so that when the HARQ process determines that atransmission subframe of the first PDU arrives, the HARQ processtransmits the second PDU to the receiving UE by using the transmissionsubframe of the second PDU; and when the MAC PDU buffer determines,according to the transmission pattern, that a minimum repetitioninterval expires, transmit the second PDU to the HARQ process again,until the quantity of times of transmission reaches the quantity oftimes of repeated transmission of the data packet, where the second PDUincludes an identifier of the transmitting HARQ process.

In an embodiment, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data.

In an embodiment, the scheduling signaling further includes identifierinformation of the transmitting UE, where the identifier information isused to indicate a priority of using a frequency domain resource by thetransmitting UE.

In an embodiment, the scheduling signaling further includes a servicetype of the user data to be transmitted by the transmitting UE.

In an embodiment, the processor 24 is further configured to: before thetransmitter 21 transmits the scheduling signaling to the receiving UE,generate the scheduling signaling; or before the transmitter 21transmits the scheduling signaling to the receiving UE, receive thescheduling signaling transmitted by a base station.

The transmitting UE in this embodiment is an entity embodimentcorresponding to the embodiment shown in FIG. 1, and theirimplementation principles and technical effects are similar, and are notfurther described herein.

FIG. 6 is a schematic structural diagram of Embodiment 1 of receivinguser equipment according to the present invention. As shown in FIG. 6,the receiving user equipment in this embodiment includes a receivingmodule 31 and a processing module 32. The receiving module 31 isconfigured to receive scheduling signaling transmitted by transmittingUE, where the scheduling signaling includes at least one of frequencydomain resource information, a quantity of cycles that can be occupied,or transmission pattern information. The processing module 32 isconfigured to receive, according to the scheduling signaling received bythe receiving module 31, user data transmitted by the transmitting UE.

According to the receiving user equipment provided by this embodiment,repeated transmission of user data is determined by transmitting UE, andis not determined according to whether there is any feedback from thereceiving UE. Therefore, if there is no feedback from the receiving UEin a D2D communication process, the transmitting UE may repeatedlytransmit the user data, and the receiving UE may repeatedly receive theuser data and perform combination processing on the received repeateddata, thereby improving reliability of data transmission.

In the receiving user equipment provided by this embodiment, a receivingmodule 31 receives scheduling signaling transmitted by transmitting UE,where the scheduling signaling includes at least one of frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information; and a processing module 32 receives,according to the scheduling signaling received by the receiving module31, user data transmitted by the transmitting UE. Therefore, if there isno feedback from the receiving UE in a D2D communication process, thetransmitting UE may repeatedly transmit the user data, and the receivingUE may repeatedly receive the user data and perform combinationprocessing on the received repeated data, thereby improving reliabilityof data transmission.

In an embodiment, the scheduling signaling further includes a quantityof times of repeated transmission of a data packet; and the processingmodule 32 is specifically configured to: repeatedly receive, accordingto the scheduling signaling received by the receiving module 31,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of times of repeatedtransmission of the data packet, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied, the user data repeatedly transmitted by the transmitting UE.

Specifically, the processing module 32 receives the data packetaccording to the frequency domain position and the transmission patternthat are included in the scheduling signaling received by the receivingmodule 31. Because the transmitting UE needs to perform repeatedtransmission for multiple times, the receiving UE needs to demodulatethe repeatedly transmitted data at a physical layer and then transmitthe data to a soft bit buffer for combination processing, and if acyclic redundancy check (CRC) check after combination is correct,deliver the data to an upper layer, or if a CRC check after combinationis incorrect, continue to wait for a next repeated data packet, until aquantity of repetitions reaches a quantity of repetitions that isspecified by the scheduling signaling. After the data is delivered tothe upper layer or a maximum quantity of repetitions is reached or newdata is received, the soft bit buffer is cleared.

In an embodiment, the processing module 32 is further configured to:transmit, according to the transmission pattern information, first userdata in a first subframe in a first frame to a second automatic repeatrequest HARQ process corresponding to the first subframe, and transmit,according to the transmission pattern information, second user data in asecond subframe in a second frame to a third HARQ process correspondingto the second subframe.

Still using a schematic diagram of UE shown in FIG. 3 as an example, thetransmitting UE transmits, in a subframe 1 in a system frame number(SFN) x, a MAC PDU 1 corresponding to an RLC 3 service, and transmits,in a subframe 2, a MAC PDU 2 corresponding to an RLC 5 service. Becausefive repetitions are required, when an SFN x+1 arrives later, the MACPDU 1 is transmitted repeatedly in the subframe 1 and the MAC PDU 2 istransmitted repeatedly in the subframe 2, until the two MAC PDUs aretransmitted for four times. The receiving UE transmits, according to thetransmission pattern information, data received in the subframe 1 in theSFN x to an HARQ process 1 for processing, and transmits data receivedin the subframe 2 in the SFN x to an HARQ process 2 for processing. Datareceived by the receiving UE in the subframe 1 in the SFN x+1 is stilltransmitted to the HARQ process 1 for processing, and data in thesubframe 2 is transmitted to the HARQ process 2 for processing. Datareceived multiple times is demodulated into soft bits at the physicallayer, and the soft bits are combined. If a CRC check after thecombination is correct, the soft bit buffer in the HARQ process iscleared.

In an embodiment, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data; and the processingmodule 32 is further configured to: receive, according to the schedulingsignaling received by the receiving module 31 and according to atransmission pattern indicated by the transmission pattern information,in a frequency domain position indicated by the frequency domainresource information, in a transmission subframe indicated by thequantity of cycles that can be occupied, the new user data transmittedby the transmitting UE.

In an embodiment, the scheduling signaling further includes a servicetype of the user data to be transmitted by the transmitting UE; and theprocessing module 32 is further configured to: create, according to theservice type, a radio link control RLC entity corresponding to theservice type; and configure parameters of the RLC entity according to aconfiguration table that is in configuration tables prestored in thereceiving UE and corresponds to the service type.

Specifically, an RLC layer of the receiving UE creates the RLC entityaccording to a service type field in the received schedulinginformation, and configures the parameters of the RLC entity accordingto the service type in the configuration table. The configuration tableis stored by the UE in a hardware device of the UE, for example, in aSIM card, or in other devices such as a communications chip, or may bestored in a memory or a random access memory (RAM) or a flash memory(flash). The RLC entity configuration parameters include a reorderingtimer time length (reordering time length) and a packet sequence numberreordering window size (reordering window size).

In the receiving user equipment provided by this embodiment, a receivingmodule 31 receives scheduling signaling transmitted by transmitting UE,where the scheduling signaling includes frequency domain resourceinformation, a quantity of cycles that can be occupied, or transmissionpattern information; and a processing module 32 receives, according tothe scheduling signaling, user data transmitted by the transmitting UE.Therefore, if there is no feedback from the receiving UE in a D2Dcommunication process, the transmitting UE may repeatedly transmit theuser data, and the receiving UE may repeatedly receive the user data andperform combination processing on the received repeated data, therebyimproving reliability of data transmission.

FIG. 7 is a schematic structural diagram of Embodiment 2 of receivinguser equipment according to the present invention. As shown in FIG. 7,the receiving user equipment in this embodiment includes a transmitter41, a receiver 42, a memory 43, and a processor 44 that is connected tothe transmitter 41, the receiver 42, and the memory 43. Certainly, theuser equipment may further include a universal component such as anantenna, a baseband processing unit, an intermediate radio frequencyprocessing unit, or an input and output apparatus, which is not limitedany longer in the embodiment of the present invention.

The receiver 42 is configured to receive scheduling signalingtransmitted by transmitting UE, where the scheduling signaling includesat least one of frequency domain resource information, a quantity ofcycles that can be occupied, or transmission pattern information; andthe processor 44 is configured to receive, according to the schedulingsignaling received by the receiver 42, user data transmitted by thetransmitting UE.

In an embodiment, the scheduling signaling further includes a quantityof times of repeated transmission of a data packet; and the processor 44is specifically configured to: repeatedly receive, according to thescheduling signaling received by the receiver 42, according to atransmission pattern indicated by the transmission pattern information,and according to the quantity of times of repeated transmission of thedata packet, in a frequency domain position indicated by the frequencydomain resource information, in a transmission subframe indicated by thequantity of cycles that can be occupied, the user data repeatedlytransmitted by the transmitting UE.

In an embodiment, the processor 44 is further configured to: transmit,according to the transmission pattern information, first user data in afirst subframe in a first frame to a second automatic repeat requestHARQ process corresponding to the first subframe, and transmit,according to the transmission pattern information, second user data in asecond subframe in a second frame to a third HARQ process correspondingto the second subframe.

In an embodiment, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data; and the processor 44 isfurther configured to: receive, according to the scheduling signalingreceived by the receiver 42 and according to a transmission patternindicated by the transmission pattern information, in a frequency domainposition indicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied, the new user data transmitted by the transmitting UE.

In an embodiment, the scheduling signaling further includes a servicetype of the user data to be transmitted by the transmitting UE; and theprocessor 44 is further configured to: create, according to the servicetype, a radio link control RLC entity corresponding to the service type;and configure parameters of the RLC entity according to a configurationtable that is in configuration tables prestored in the receiving UE andcorresponds to the service type.

The receiving UE in this embodiment is an entity embodimentcorresponding to the embodiment shown in FIG. 6, and theirimplementation principles and technical effects are similar, and are notfurther described herein.

FIG. 8 is a flowchart of Embodiment 1 of a method for data transmissionin D2D communication according to the present invention. As shown inFIG. 8, the method for data transmission in D2D communication in thisembodiment includes:

S101. Transmitting UE transmits scheduling signaling to receiving UE,where the scheduling signaling includes at least one of frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information.

Specifically, the frequency domain resource information in thescheduling information in this embodiment may include a frequency domainresource index or a maximum frequency domain resource range. If only oneuser transmits data at a same transmission time, the frequency domainresource information may be a maximum frequency domain resource range.If multiple users transmit data at a same transmission time, thefrequency domain resource information is a frequency domain resourceindex, and the quantity of cycles that can be occupied is used toindicate a quantity of cycles that can be occupied by user datatransmitted by the transmitting UE.

For a transmission pattern in the scheduling signaling in thisembodiment, refer to the schematic diagram of the transmission patternshown in FIG. 2 and related descriptions.

Specifically, the scheduling signaling in this embodiment may include atleast one of the frequency domain resource information, the quantity ofcycles that can be occupied, and the transmission pattern information.If only one or two of the information are included, the other two or oneof the information is fixed.

For example, in a scenario in which the scheduling signaling in thisembodiment includes only the frequency domain resource information, thetransmission pattern information and the quantity of cycles that can beoccupied are fixed. In a scenario in which the scheduling signaling inthis embodiment includes only the quantity of cycles that can beoccupied, the frequency domain resource information and the transmissionpattern information are fixed. It may be specified that a fixedcorrespondence exists between a frequency domain position occupied bythe scheduling signaling and a frequency domain position occupied by theuser data. For example, if the scheduling signaling is transmitted in athird symbol of every two PRBs, data information is transmitted in anysymbol except the third symbol and a pilot symbol in the two PRBs. In ascenario in which the scheduling signaling in this embodiment includesonly the transmission pattern information, the frequency domain resourceinformation and the quantity of cycles that can be occupied are fixed.

S102. The transmitting UE transmits user data to the receiving UEaccording to the scheduling signaling, so that the receiving UE receivesthe user data according to the scheduling signaling.

Specifically, the transmitting UE transmits the to-be-transmitted userdata according to the frequency domain resource information, thequantity of cycles that can be occupied, and the transmission patterninformation in the scheduling signaling, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied; and the receiving UE receives, according to the transmissionpattern indicated by the transmission pattern information, in thefrequency domain position indicated by the frequency domain resourceinformation, in the transmission subframe indicated by the quantity ofcycles that can be occupied, the user data transmitted by thetransmitting UE.

In the method for data transmission in D2D communication according tothis embodiment, repeated transmission of user data is determined bytransmitting UE, and is not determined according to whether there is anyfeedback from receiving UE. Therefore, if there is no feedback from thereceiving UE in a D2D communication process, the transmitting UE mayrepeatedly transmit the user data, and the receiving UE may repeatedlyreceive the user data and perform combination processing on the receivedrepeated data, thereby improving reliability of data transmission.

In the method for data transmission in D2D communication according tothis embodiment, transmitting UE transmits scheduling signaling toreceiving UE, where the scheduling signaling includes frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information; and the transmitting UE transmits userdata to the receiving UE according to the scheduling signaling, so thatthe receiving UE receives the user data according to the schedulingsignaling. Therefore, if there is no feedback from the receiving UE in aD2D communication process, the transmitting UE may repeatedly transmitthe user data, and the receiving UE may repeatedly receive the user dataand perform combination processing on the received repeated data,thereby improving reliability of data transmission.

In an embodiment, the scheduling signaling further includes a quantityof times of repeated transmission of a data packet; and

Step S102 may include: repeatedly transmitting, by the transmitting UE,the user data to the receiving UE according to the scheduling signaling,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of times of repeatedtransmission of the data packet, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied.

In an embodiment, the repeatedly transmitting, by the transmitting UE,the user data to the receiving UE according to the scheduling signaling,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of times of repeatedtransmission of the data packet, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied, includes: obtaining, by an HARQ process of the transmittingUE, a first PDU in a MAC PDU buffer, and recording a quantity of timesof transmission as o; and if the HARQ process of the transmitting UEdetermines, according to an identifier of the HARQ process and thetransmission pattern, that a transmission subframe of the first PDUarrives, transmitting the first PDU to the receiving UE by using thetransmission subframe of the first PDU, and adding 1 to the quantity oftimes of transmission, until the quantity of times of transmissionreaches the quantity of times of repeated transmission of the datapacket.

For an RLC module and a MAC module included in the UE in thisembodiment, a PDU buffer and the HARQ process included in the MACmodule, and a processing procedure of the transmitting UE, refer to theschematic diagram of the UE shown in FIG. 3 and related descriptions.

For a correspondence between a transmission subframe number and an HARQprocess identifier in this embodiment, refer to the schematic diagram ofa correspondence between a transmission subframe number and an HARQprocess identifier shown in FIG. 4 and related descriptions.

Further, if a resource corresponding to a first HARQ process isallocated to another transmitting UE for use, the transmitting UE stopsusing the first HARQ process after the quantity of times of transmissionreaches the quantity of times of repeated transmission of the datapacket.

For example, processing after the transmission pattern of thetransmitting UE is changed is described in this embodiment. When UE B ina D2D group has service data of a higher priority for transmission, atransmission resource of UE A is preempted by UE B, and transmissionresources of UE A are reduced. For example, in each frame, two subframesthat may transmit data of UE A are reduced to only one subframe that maytransmit data of UE A. Therefore, a case in which data in an HARQprocess buffer cannot be transmitted again but a quantity of times ofrepeated transmission is not completed yet may occur, and this isbecause the HARQ process is associated with a transmission subframenumber. To ensure reliable data transmission, UE A may not use theprocess any longer after continuing to repeatedly transmit the data inthe HARQ process buffer for a remaining quantity of times. Afterobtaining information indicating that the resource may be used, UE Bstarts to use the resource after waiting for a period equal to aquantity of repetitions multiplied by a repetition interval.

In the method for data transmission in D2D communication according tothis embodiment, transmitting UE transmits scheduling signaling toreceiving UE, where the scheduling signaling includes frequency domainresource information, a quantity of cycles that can be occupied,transmission pattern information, and a quantity of times of repeatedtransmission of a data packet; and the transmitting UE repeatedlytransmits user data to the receiving UE according to the schedulingsignaling, according to a transmission pattern indicated by thetransmission pattern information, and according to the quantity of timesof repeated transmission of the data packet, in a frequency domainposition indicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied. Therefore, if there is no feedback from the receiving UE in aD2D communication process, the transmitting UE may repeatedly transmitthe user data, and the receiving UE may repeatedly receive the user dataand perform combination processing on the received repeated data,thereby improving reliability of data transmission.

In an embodiment, the repeatedly transmitting, by the transmitting UE,the user data to the receiving UE according to the scheduling signaling,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of times of repeatedtransmission of the data packet, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied, includes: transmitting, by a MAC PDU buffer of thetransmitting UE, a second PDU to an HARQ process of the transmitting UE,and recording a quantity of times of transmission as 1, so that when theHARQ process determines that a transmission subframe of the first PDUarrives, the HARQ process transmits the second PDU to the receiving UEby using the transmission subframe of the second PDU; and when the MACPDU buffer of the transmitting UE determines, according to thetransmission pattern, that a minimum repetition interval expires,transmitting the second PDU to the HARQ process again, until thequantity of times of transmission reaches the quantity of times ofrepeated transmission of the data packet, where the second PDU includesan identifier of the transmitting HARQ process.

Specifically, after the HARQ process fetches data, the MAC PDU buffer ofthe transmitting end may continue to reserve the PDU, and change acounter value from Current_TX_NB to Current_TX_NB+1. The HARQ processfetches data from a MAC PDU when performing transmission every time, andthe MAC PDU buffer provides appropriate data to the HARQ processaccording to a transmission status and a repetition status of a PDU. Forexample, if the transmitting UE obtains transmission capabilities of twoconsecutive subframes in a frame, a first subframe transmits a MAC PDU1, and a second subframe must transmit a MAC PDU 2 and cannot continueto transmit the MAC PDU 1, because the scheduling signaling requiresthat a repeated transmission interval of each packet should not be o.Therefore, when the repeated transmission interval is satisfied, the MACPDU buffer provides a repeated data packet to the HARQ process, and acase in which data packets transmitted at the first time andsubsequently repeatedly transmitted use different subframe numbers mayoccur. In this case, the transmitting UE needs to notify, in the datapacket, a process number used by the transmitting UE to the receivingend, so that the receiving UE can combine the received repeated data.After receiving a new data packet, the receiving UE demodulates the datapacket into soft bits and then transmits the soft bits to an HARQprocess buffer corresponding to the data packet, and after a repeatedpacket of the data packet arrives, also transmits soft bits to acorresponding HARQ process buffer according to a process number carriedin the repeated packet and performs combination.

In the method for data transmission in D2D communication according tothis embodiment, transmitting UE transmits scheduling signaling toreceiving UE, where the scheduling signaling includes frequency domainresource information, a quantity of cycles that can be occupied,transmission pattern information, and a quantity of times of repeatedtransmission of a data packet; and the transmitting UE repeatedlytransmits user data to the receiving UE according to the schedulingsignaling, according to a transmission pattern indicated by thetransmission pattern information, and according to the quantity of timesof repeated transmission of the data packet, in a frequency domainposition indicated by the frequency domain resource information, in atransmission subframe indicated by the quantity of cycles that can beoccupied. Therefore, if there is no feedback from the receiving UE in aD2D communication process, the transmitting UE may repeatedly transmitthe user data, and the receiving UE may repeatedly receive the user dataand perform combination processing on the received repeated data,thereby improving reliability of data transmission.

In an embodiment, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data.

Specifically, if the user data to be transmitted by the transmitting UEis new data, the scheduling signaling further includes the indicationthat the data packet is new data; if the user data to be transmitted bythe transmitting UE is data that is transmitted repeatedly, thescheduling signaling does not include the indication that the datapacket is new data.

In an embodiment, the scheduling signaling further includes identifierinformation of the transmitting UE, where the identifier information isused to indicate a priority of using a frequency domain resource by thetransmitting UE.

Specifically, the identifier information of the UE may be a globalidentifier in a large area, or may be an intra-group identifierallocated by a group owner. The identifier information of the UE has ameaning indicating a priority. If another UE also uses a same resource,after the UE detects a collision, UE having smaller UE identifierinformation may preferentially use the resource.

In an embodiment, the scheduling signaling further includes a servicetype of the user data to be transmitted by the transmitting UE.

In an embodiment, before the transmitting UE transmits the schedulingsignaling to the receiving UE, the method further includes: generating,by the transmitting UE, the scheduling signaling; or receiving, by thetransmitting UE, the scheduling signaling transmitted by a base station.

Specifically, the scheduling signaling transmitted by the transmittingUE to the receiving UE may be generated by the transmitting UE, or maybe received by the transmitting UE from the base station.

In the method for data transmission in D2D communication according tothis embodiment, transmitting UE transmits scheduling signaling toreceiving UE, where the scheduling signaling includes frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information; and the transmitting UE transmits userdata to the receiving UE according to the scheduling signaling, so thatthe receiving UE receives the user data according to the schedulingsignaling. Therefore, if there is no feedback from the receiving UE in aD2D communication process, the transmitting UE may repeatedly transmitthe user data, and the receiving UE may repeatedly receive the user dataand perform combination processing on the received repeated data,thereby improving reliability of data transmission.

Embodiment 1 of the foregoing method for data transmission in D2Dcommunication may be performed by the transmitting UE in FIG. 1 or FIG.5.

FIG. 9 is a flowchart of Embodiment 2 of a method for data transmissionin D2D communication according to the present invention. As shown inFIG. 9, the method for data transmission in D2D communication in thisembodiment includes:

S501. Receiving UE receives scheduling signaling transmitted bytransmitting UE, where the scheduling signaling includes at least one offrequency domain resource information, a quantity of cycles that can beoccupied, or transmission pattern information.

S502. The receiving UE receives, according to the scheduling signaling,user data transmitted by the transmitting UE.

In the method for data transmission in D2D communication according tothis embodiment, repeated transmission of user data is determined bytransmitting UE, and is not determined according to whether there is anyfeedback from receiving UE. Therefore, if there is no feedback from thereceiving UE in a D2D communication process, the transmitting UE mayrepeatedly transmit the user data, and the receiving UE may repeatedlyreceive the user data and perform combination processing on the receivedrepeated data, thereby improving reliability of data transmission.

In the method for data transmission in D2D communication according tothis embodiment, receiving UE receives scheduling signaling transmittedby transmitting UE, where the scheduling signaling includes frequencydomain resource information, a quantity of cycles that can be occupied,or transmission pattern information; and the receiving UE receives,according to the scheduling signaling, user data transmitted by thetransmitting UE. Therefore, if there is no feedback from the receivingUE in a D2D communication process, the transmitting UE may repeatedlytransmit the user data, and the receiving UE may repeatedly receive theuser data and perform combination processing on the received repeateddata, thereby improving reliability of data transmission.

In an embodiment, the scheduling signaling further includes a quantityof times of repeated transmission of a data packet; and

Step S502 may include: repeatedly receiving, by the receiving UEaccording to the scheduling signaling, according to a transmissionpattern indicated by the transmission pattern information, and accordingto the quantity of times of repeated transmission of the data packet, ina frequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied, the user data repeatedly transmitted by thetransmitting UE.

Specifically, the receiving UE receives the data packet according to thefrequency domain position and the transmission pattern information thatare included in the previously received scheduling signaling. Becausethe transmitting UE needs to perform repeated transmission for multipletimes, the receiving UE needs to demodulate the repeatedly transmitteddata at a physical layer and then transmit the data to a soft bit bufferfor combination processing, and if a CRC check after combination iscorrect, deliver the data to an upper layer, or if a CRC check aftercombination is incorrect, continue to wait for a next repeated datapacket, until a quantity of repetitions reaches a quantity ofrepetitions that is specified by the scheduling signaling. After thedata is delivered to the upper layer or a maximum quantity ofrepetitions is reached or new data is received, the soft bit buffer iscleared.

In an embodiment, the repeatedly receiving, by the receiving UEaccording to the scheduling signaling, according to a transmissionpattern indicated by the transmission pattern information, and accordingto the quantity of times of repeated transmission of the data packet, ina frequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by the quantity ofcycles that can be occupied, the user data repeatedly transmitted by thetransmitting UE, includes: transmitting, by the receiving UE accordingto the transmission pattern information, first user data in a firstsubframe in a first frame to a second automatic repeat request HARQprocess corresponding to the first subframe, and transmitting, by thereceiving UE according to the transmission pattern information, seconduser data in a second subframe in a second frame to a third HARQ processcorresponding to the second subframe.

Still using a schematic diagram of UE shown in FIG. 3 as an example, thetransmitting UE transmits, in a subframe 1 in an SFN x, a MAC PDU 1corresponding to an RLC 3 service, and transmits, in a subframe 2, a MACPDU 2 corresponding to an RLC 5 service. Because five repetitions arerequired, when an SFN x+1 arrives later, the MAC PDU 1 is transmittedrepeatedly in the subframe 1 and the MAC PDU 2 is transmitted repeatedlyin the subframe 2, until the two MAC PDUs are transmitted for fourtimes. The receiving UE transmits, according to the transmission patterninformation, data received in the subframe 1 in the SFN x to an HARQprocess 1 for processing, and transmits data received in the subframe 2in the SFN x to an HARQ process 2 for processing. Data received by thereceiving UE in the subframe 1 in the SFN x+1 is still transmitted tothe HARQ process 1 for processing, and data in the subframe 2 istransmitted to the HARQ process 2 for processing. Data received multipletimes is demodulated into soft bits at the physical layer, and the softbits are combined. If a CRC check after the combination is correct, thesoft bit buffer in the HARQ process is cleared.

In an embodiment, the scheduling signaling further includes anindication that a data packet is new data, where the indication that thedata packet is new data is used to indicate that the user data to betransmitted by the transmitting UE is new data; and that the receivingUE receives, according to the scheduling signaling, user datatransmitted by the transmitting UE, includes: receiving, by thereceiving UE according to the scheduling signaling and according to atransmission pattern indicated by the transmission pattern information,in a frequency domain position indicated by the frequency domainresource information, in a transmission subframe indicated by thequantity of cycles that can be occupied, the new user data transmittedby the transmitting UE.

In an embodiment, the scheduling signaling further includes a servicetype of the user data to be transmitted by the transmitting UE; and themethod in this embodiment further includes: creating, by the receivingUE according to the service type, a radio link control RLC entitycorresponding to the service type; and configuring, by the receiving UE,parameters of the RLC entity according to a configuration table that isin configuration tables prestored in the receiving UE and corresponds tothe service type.

Specifically, an RLC layer of the receiving UE creates the RLC entityaccording to a service type field in the received schedulinginformation, and configures the parameters of the RLC entity accordingto the service type in the configuration table. The configuration tableis stored by the UE in a hardware device of the UE, for example, in aSIM card, or in other devices such as a communications chip, or may bestored in a memory or a RAM or a flash. The RLC entity configurationparameters include a reordering timer time length and a packet sequencenumber reordering window size.

In the method for data transmission in D2D communication according tothis embodiment, receiving UE receives scheduling signaling transmittedby transmitting UE, where the scheduling signaling includes frequencydomain resource information, a quantity of cycles that can be occupied,or transmission pattern information; and the receiving UE receives,according to the scheduling signaling, user data transmitted by thetransmitting UE. Therefore, if there is no feedback from the receivingUE in a D2D communication process, the transmitting UE may repeatedlytransmit the user data, and the receiving UE may repeatedly receive theuser data and perform combination processing on the received repeateddata, thereby improving reliability of data transmission.

Embodiment 2 of the foregoing method for data transmission in D2Dcommunication may be performed by the transmitting UE in FIG. 6 or FIG.7.

The following describes a method for data transmission in D2Dcommunication according to the present invention by using an interactionprocess between transmitting UE and receiving UE as an example.

FIG. 10 is a flowchart of Embodiment 3 of a method for data transmissionin D2D communication according to the present invention. As shown inFIG. 10, the method for data transmission in D2D communication in thisembodiment includes:

S601. Transmitting UE transmits scheduling signaling to receiving UE,where the scheduling signaling includes at least one of frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information.

S602. The transmitting UE transmits user data to the receiving UEaccording to the scheduling signaling.

S603. The receiving UE receives, according to the scheduling signaling,the user data transmitted by the transmitting UE.

In the method for data transmission in D2D communication according tothis embodiment, transmitting UE transmits scheduling signaling toreceiving UE, where the scheduling signaling includes frequency domainresource information, a quantity of cycles that can be occupied, ortransmission pattern information; the transmitting UE transmits userdata to the receiving UE according to the scheduling signaling; and thereceiving UE receives, according to the scheduling signaling, the userdata transmitted by the transmitting UE. Therefore, if there is nofeedback from the receiving UE in a D2D communication process, thetransmitting UE may repeatedly transmit the user data, and the receivingUE may repeatedly receive the user data and perform combinationprocessing on the received repeated data, thereby improving reliabilityof data transmission.

In the several embodiments provided in the present invention, it shouldbe understood that the disclosed apparatus and method may be implementedin other manners. For example, the described apparatus embodiment ismerely exemplary. For example, the unit division is merely logicalfunction division and may be other division in actual implementation.For example, a plurality of units or components may be combined orintegrated into another system, or some features may be ignored or notperformed. In addition, the displayed or discussed mutual couplings ordirect couplings or communication connections may be implemented byusing some interfaces. The indirect couplings or communicationconnections between the apparatuses or units may be implemented inelectronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit. The integrated unit may be implemented in a form ofhardware, or may be implemented in a form of hardware in addition to asoftware functional unit.

When the foregoing integrated unit is implemented in a form of asoftware functional unit, the integrated unit may be stored in acomputer-readable storage medium. The software functional unit is storedin a storage medium and includes several instructions for instructing acomputer device (which may be a personal computer, a server, or anetwork device) or a processor to perform a part of the steps of themethods described in the embodiments of the present invention. Theforegoing storage medium includes: any medium that can store programcode, such as a USB flash drive, a removable hard disk, a read-onlymemory (ROM), a random access memory (RAM), a magnetic disk, or anoptical disc.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, division of theforegoing function modules is taken as an example for illustration. Inactual application, the foregoing functions can be allocated todifferent function modules and implemented according to a requirement,that is, an inner structure of an apparatus is divided into differentfunction modules to implement all or part of the functions describedabove. For a detailed working process of the foregoing apparatus,reference may be made to a corresponding process in the foregoing methodembodiments, and details are not described herein again.

Finally, it should be noted that the foregoing embodiments are merelyintended for describing the technical solutions of the presentinvention, but not for limiting the present invention. Although thepresent invention is described in detail with reference to the foregoingembodiments, persons of ordinary skill in the art should understand thatthey may still make modifications to the technical solutions describedin the foregoing embodiments or make equivalent replacements to some orall technical features thereof, without departing from the scope of thetechnical solutions of the embodiments of the present invention.

What is claimed is:
 1. A first user equipment (UE) comprising: one ormore processors; and a non-transitory computer-readable storage mediumstoring a program to be executed by the one or more processors, theprogram including instructions for: transmitting scheduling signaling toa second UE, the scheduling signaling comprising frequency domainresource information and transmission pattern information, thetransmission pattern information comprising a time duration fortransmitting a data in a cycle and a repetition mode of the data,wherein the repetition mode is one of: an immediate repetition in whichtransmission of a same data is permitted at a next availabletransmission time; or a discontinuous repetition and a minimumrepetition interval in which a transmission of a same data is permittedafter waiting a period of time, the period of time being longer than atime to the next available transmission time; performing a firsttransmission of the data to the second UE according to the schedulingsignaling; and performing a retransmission of the data to the second UEaccording to the scheduling signaling that is used with the firsttransmission of the data to the second UE.
 2. The first UE according toclaim 1, wherein: the scheduling signaling further comprises a quantityof repetitions of a data packet; and the instructions for performing theretransmission of the data to the second UE according to the schedulingsignaling comprises instructions for retransmitting the data, accordingto a transmission pattern indicated by the transmission patterninformation, and according to the quantity of repetitions of the datapacket, in a frequency domain position indicated by the frequency domainresource information, in a transmission subframe indicated by a quantityof cycles that can be occupied.
 3. The first UE according to claim 1,wherein the scheduling signaling further comprises an indication that adata packet is new data, wherein the indication that the data packet isnew data is used to indicate that the data to be transmitted by thefirst UE is new data.
 4. The first UE according to claim 1, wherein thescheduling signaling further comprises identifier information of thefirst UE, wherein the identifier information is used to indicate apriority of using a frequency domain resource by the first UE.
 5. Thefirst UE according to claim 1, wherein the scheduling signaling furthercomprises a service type of the data to be transmitted by the first UE.6. The first UE according to claim 1, wherein the program furtherincludes instructions for: before transmitting the scheduling signalingto the second UE, generating the scheduling signaling; or beforetransmitting the scheduling signaling to the second UE, receiving thescheduling signaling transmitted by a base station.
 7. A second userequipment (UE) comprising: one or more processors; and a non-transitorycomputer-readable storage medium storing a program to be executed by theone or more processors, the program including instructions for:receiving scheduling signaling from a first UE, the scheduling signalingcomprising of frequency domain resource information and transmissionpattern information, the transmission pattern information comprising atime duration for transmitting a data in a cycle and a repetition modeof the data, wherein the repetition mode is one of: an immediaterepetition in which transmission of a same data is permitted at a nextavailable transmission time; or a discontinuous repetition and a minimumrepetition interval in which a transmission of a same data is permittedafter waiting a period of time, the period of time being longer than atime to the next available transmission time; receiving the data in afirst transmission from the first UE, according to information in thescheduling signaling received from the first UE; and receiving the datain a retransmission from the first UE, according to the information inthe scheduling signaling received from the first UE and used forreceiving the data in the first transmission from the first UE.
 8. Thesecond UE according to claim 7, wherein: the scheduling signalingfurther comprises a quantity of repetitions of a data packet; and theinstructions for receiving the data in the retransmission, according tothe information in the scheduling signaling received from the first UE,comprises instructions for receiving the data in the retransmission,according to a transmission pattern indicated by the transmissionpattern information, and according to the quantity of repetitions of thedata packet, in a frequency domain position indicated by the frequencydomain resource information, in a transmission subframe indicated by aquantity of cycles that can be occupied, of the data from the first UE.9. The second UE according to claim 7, wherein: the scheduling signalingfurther comprises an indication that a data packet is new data, theindication that the data packet is new data indicating that the datafrom the first UE is new data; and the instructions for receiving thefirst transmission, according to the information in the schedulingsignaling received from the first UE comprise instructions for receivingthe first transmission, according to a transmission pattern indicated bythe transmission pattern information, in a frequency domain positionindicated by the frequency domain resource information, in atransmission subframe indicated by a quantity of cycles that can beoccupied, of the new data from the first UE.
 10. The second UE accordingto claim 7, wherein: the scheduling signaling further comprises aservice type of the data; and the program further includes instructionsfor: creating, according to the service type, a radio link control (RLC)entity corresponding to the service type; and configuring parameters ofthe RLC entity according to a configuration table pre-stored in thesecond UE and that corresponds to the service type.
 11. A method fordata transmission, comprising: transmitting, by a first user equipment(UE), scheduling signaling to a second UE, wherein the schedulingsignaling comprises of frequency domain resource information andtransmission pattern information, the transmission pattern informationcomprising a time duration for transmitting a data in a cycle and arepetition mode of the data, wherein the repetition mode is one of: animmediate repetition in which transmission of a same data is permittedat a next available transmission time; or a discontinuous repetition anda minimum repetition interval in which a transmission of a same data ispermitted after waiting a period of time, the period of time beinglonger than a time to the next available transmission time; performing,by the first UE, a first transmission of data to the second UE accordingto the scheduling signaling; and performing, by the first UE, aretransmission of the data to the second UE according to the schedulingsignaling used for the first transmission of the data to the second UE.12. The method according to claim 11, wherein the scheduling signalingfurther comprises a quantity of repetitions of a data packet; and thetransmitting, by the first UE, the data to the second UE according tothe scheduling signaling, comprises: performing, by the first UE, theretransmission of the data to the second UE according to the schedulingsignaling comprises repeated retransmitting, by the first UE, the datato the second UE, according to the scheduling signaling, according to atransmission pattern indicated by the transmission pattern information,and according to the quantity of repetitions of the data packet, in afrequency domain position indicated by the frequency domain resourceinformation, in a transmission subframe indicated by a quantity ofcycles that can be occupied.
 13. The method according to claim 11,wherein the scheduling signaling further comprises an indication that adata packet is new data, wherein the indication that the data packet isnew data indicates that the data to be transmitted by the first UE isnew data.
 14. The method according to claim 11, wherein the schedulingsignaling further comprises identifier information of the first UE,wherein the identifier information indicates a priority of using afrequency domain resource by the first UE.
 15. The method according toclaim 11, wherein the scheduling signaling further comprises a servicetype of the data to be transmitted by the first UE.
 16. The methodaccording to claim 11, wherein before the transmitting, by the first UE,the scheduling signaling to the second UE, the method further comprises:generating, by the first UE, the scheduling signaling; or receiving, bythe first UE, the scheduling signaling from a base station.
 17. A methodfor data transmission, the method comprising: receiving, by a first userequipment (UE), scheduling signaling from a second UE, wherein thescheduling signaling comprises frequency domain resource information andtransmission pattern information, the transmission pattern informationcomprising a time duration for transmitting a data in a cycle and arepetition mode of the data, wherein the repetition mode is one of: animmediate repetition in which transmission of a same data is permittedat a next available transmission time; or a discontinuous repetition anda minimum repetition interval in which a transmission of a same data ispermitted after waiting a period of time, the period of time beinglonger than a time to the next available transmission time; receiving,by the first UE, a first transmission, according to information in thescheduling signaling, of the data from the second UE; and receiving, bythe first UE, a retransmission of the data from the second UE, accordingto the information in the scheduling signaling used for receiving thefirst transmission of the data from the second UE.
 18. The methodaccording to claim 17, wherein: the scheduling signaling furthercomprises a quantity of repetitions of a data packet; and receiving, bythe first UE, the retransmission of the data from the second UE,according to the information in the scheduling signaling, comprisesreceiving, by the first UE, the retransmission of the data from thesecond UE, according to a transmission pattern indicated by thetransmission pattern information, and according to the quantity ofrepetitions of the data packet, in a frequency domain position indicatedby the frequency domain resource information, in a transmission subframeindicated by a quantity of cycles that can be occupied.
 19. The methodaccording to claim 17, wherein: the scheduling signaling furthercomprises an indication that a data packet is new data, wherein theindication that the data packet is new data indicates that the data fromthe second UE is new data; and receiving, by the first UE, theretransmission of the data from the second UE, according to thescheduling signaling, comprises receiving, by the first UE, according toa transmission pattern indicated by the transmission patterninformation, in a frequency domain position indicated by the frequencydomain resource information, in a transmission subframe indicated by aquantity of cycles that can be occupied.
 20. The method according toclaim 17, wherein: the scheduling signaling further comprises a servicetype of the data; and the method further comprises: creating, by thefirst UE according to the service type, a radio link control (RLC)entity corresponding to the service type; and configuring, by the firstUE, parameters of the RLC entity according to a configuration tablepre-stored in the first UE and corresponds to the service type.